X11TK: Introduce Thai support and rewrite/cleanup messagebox positioning code (#14474)

src/core/unix/SDL_libthai.c

@@ -0,0 +1,76 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+*/
+#include "SDL_internal.h"
+
+#ifdef HAVE_LIBTHAI_H
+
+#include "SDL_libthai.h"
+
+#ifdef SDL_LIBTHAI_DYNAMIC
+SDL_ELF_NOTE_DLOPEN(
+    "Thai",
+    "Thai language support",
+    SDL_ELF_NOTE_DLOPEN_PRIORITY_SUGGESTED,
+    SDL_LIBTHAI_DYNAMIC
+);
+#endif
+
+
+SDL_LibThai *SDL_LibThai_Create(void)
+{
+    SDL_LibThai *th;
+
+    th = (SDL_LibThai *)SDL_malloc(sizeof(SDL_LibThai));
+    if (!th) {
+        return NULL;
+    }
+
+#ifdef SDL_LIBTHAI_DYNAMIC
+    #define SDL_LIBTHAI_LOAD_SYM(a, x, n, t) x = ((t)SDL_LoadFunction(a->lib, n)); if (!x) { SDL_UnloadObject(a->lib); SDL_free(a); return NULL; }
+
+    th->lib = SDL_LoadObject(SDL_LIBTHAI_DYNAMIC);
+    if (!th->lib) {
+        SDL_free(th);
+        return NULL;
+    }
+
+    SDL_LIBTHAI_LOAD_SYM(th, th->make_cells, "th_make_cells", SDL_LibThaiMakeCells);
+#else
+    th->make_cells = th_make_cells;
+#endif
+
+    return th;
+}
+
+void SDL_LibThai_Destroy(SDL_LibThai *th)
+{
+    if (!th) {
+        return;
+    }
+
+#ifdef SDL_LIBTHAI_DYNAMIC
+    SDL_UnloadObject(th->lib);
+#endif
+
+    SDL_free(th);
+}
+
+#endif

src/core/unix/SDL_libthai.h

@@ -0,0 +1,43 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+*/
+
+#include "SDL_internal.h"
+
+#ifndef SDL_libthai_h_
+#define SDL_libthai_h_
+
+#ifdef HAVE_LIBTHAI_H
+#include <thai/thcell.h>
+
+typedef size_t (*SDL_LibThaiMakeCells)(const thchar_t *s, size_t, struct thcell_t cells[], size_t *, int);
+
+typedef struct SDL_LibThai {
+    SDL_SharedObject *lib;
+ 
+    SDL_LibThaiMakeCells make_cells;
+} SDL_LibThai;
+
+extern SDL_LibThai *SDL_LibThai_Create(void);
+extern void SDL_LibThai_Destroy(SDL_LibThai *th);
+
+#endif // HAVE_LIBTHAI_H
+
+#endif // SDL_libthai_h_